antenna

We’ve seen our share of commercially available HDTV antennas that work really poorly. For at least four years now we’ve gone without cable television, using a coat hanger antenna we made ourselves to record over-the-air broadcasts. But it’s a pretty ugly beast — we’re lucky enough to have an attic in which it can be hidden. If you’re in need of free television and don’t want an eyesore of a an antenna try building this foil and cardboard version. Even it if doesn’t work at all you’re only out about ten bucks.

The expensive part is the matching transformer which converts screw terminals to a coaxial cable connection so that it may be connected to your HDTV. You’ll need a few nuts and bolts, but we assume you can beg, borrow, or steal the tin foil, cardboard, and glue that round out the parts list. Glue, measure, cut, fold, fasten, finished! You’ll be watching horrible summer TV in no time!

[Danilo Larizza] is sharing a network connection between a couple of apartments. They are not far apart, but they are also not right next to each other so a set of external antennas is necessary. He built this 2.4 GHz biquad antenna on the cheap (translated) just to test if it improved the signal before he tried to buy a proper antenna. It turns out to work well enough that this is all that he needs.

The antenna itself is about one meter of thick wire bent into two squares which are 31mm on each side. The coaxial cable going to the router connects to the center portion of this antenna. For a bit better directional reception he added some tin foil as a reflector. Since this is outdoors he used a food storage container for protection (the antenna is mounted to the lid, the body has been removed for this picture). The whole things is perched on a stake in a flower pot with proper line of sight to the other antenna.

This RC truck can be controlled with the tip of your thumb or the tilt of a wrist. That’s thanks to the IOIO which was inserted in place of the toy’s original controller. [Exanko] made the hardware changes in order to use his Android phone as the controller. The white circle is a software joystick that acts as throttle when your thumb moves along the Y axis, and steering when it moves along the X axis. But while he was at it he also included accelerometer input as an alternative control option.

The IOIO board has a Bluetooth dongle connected to its USB port as a means of wireless communication. The dongle was hacked to accept an external antenna, thereby increasing the truck’s range. There is also some on-board flair like LEDs for lights and even a laser diode for… well we’re not sure what that’s for. Get a better look at the hardware internals in the clip after the break.

We can’t wait to give this one a try. We’ve got a DIY HDTV antenna hanging out in the attic which was made from some scrap wood and eight metal coat hangers. It works great but it’s pretty ugly and not everyone has an attic to hide it in (not to mention the signal drop caused by the roof shingles). This is a fractal antenna anchored to some clear plastic so you can just hang it in the window and start picking up the over-the-air channels without much effort.

The pattern was modeled in SketchUp then printed out on two pieces of paper. One piece had it printed on both sides, which makes it easy to glue on a sheet of aluminum foil, then follow the pattern on the opposite side to cut out the important parts. The other template was used as an aligment guide when gluing the foil to the clear plastic. A coaxial adapter was then attached using nuts and machine screws. If you build it, let us know how it comes out!

Teensy CNC mill

The guys at Inventables put together a neat CNC router kit that looks very interesting. It uses Makerslide linear bearings and CNC’d parts to make a surprisingly cheap frame for something that can engrave wood and metal. Inventables is running a Kickstarter-esque preorder to fund this production run but right now they’re 30 orders short. We’d like to see how these routers turn out in the real world, so if you’re on the fence (or just want a CNC router), this might be the time to buy.

DIY solder fume extractor

[Jared] sent in a fume extractor he put together. It’s a small PC case fan with a carbon filter sandwiched between a pair of grilles. Not much, but if should keep those wonderful flux fumes away from your face.

A million fake Internet points to the first person to come up with a DIY clone

[filespace] shared an awesome Electrofishing video with us. Electrofishing pulses a DC current through two electrodes attached to a boat. This current causes galvanotaxis in fish, causing them to swim towards the anode. The fish can be caught with a net and released afterwards; there’s no damage to the fish at all. We’d love to see a DIY solution, but throwing M-80s into a lake doesn’t count.

Improving GSM reception with a bit of metal

[Raivis] lives in the country, so even his voice reception on GSM is terrible, let alone data. Inspired by an earlier post, [Raivis] built a discone antenna to improve his cell signal. Now everything is crystal clear and his Huawei E1752 USB/GSM modem improved from 3 mbps down to 5 mbps down.

CNC halftone photos

[Dana] sent in a few pics of a project he’s working on. He’s making halftone prints with a CNC and metal. We’ve seen this before, but we’re really loving [Dana]’s take on it. He’s using two-layer engraving plastic with a .005” engraving tool on his CNC. There’s a gallery of his work after the break; [Dana]’s portrait is 14000+ dots and took 6 hours, his bosses kids are 16000+ dots and took 4 hours, and [Dana]’s niece is 5500 dots and took 35 minutes. Very awesome work, and now [Dana] has fulfilled a lifelong dream of machining his face.

Turning anything into a touch sensor

Makey Makey is a small board with a USB plug and bunch of contact points for alligator clips. Plug the Makey into your computer and attach just about anything to the contacts, and you can make anything into a video game controller, a keyboard, a piano, or pretty much anything you can imagine. If [Sprite_tm] copied it, you know it has to be cool.

RepRaps will finally cost a million dollars

The Pentagon is throwing money at 3D printers. It’s “only” $60 Million the DoD is putting into 3d printer research, but hopefully our most brilliant researchers will help refine some of the ‘unsolved problems’ – like metal and circuit printing – the 3D printer community is facing.

Getting started with FPGAs

[Tim] found a neat little $40 FPGA board aimed right at the hobby hacker. The good news: It’s compatible with Arduino shields, and it’s very cheap. The bad news: it only has 1280 logic cells, so you probably won’t be emulating CPUs on this thing. If anyone has a teardown / project with this board, send it in.

Improving a Bluetooth dongle with a bit of wire

Unsurprisingly, the extremely cheap Bluetooth dongle [Mike] bought on eBay didn’t have great reception or range. No problem, because you can just replace the internal antenna with a piece of wire cut to length. Now bluetooth devices are recognized instantly, and there are no Bluetooth ‘dead spots’ around [Mike]’s computer.

Come to France, make stuff

The Toulouse Hackerspace is having a little shindig this coming weekend (May 25-27) featuring a conference, workshop, concerts and performances. If you’re in the area, drop on by,

The NRF 24L01+ radio transceiver can be found in a lot of wireless project builds. But it’s only meant to work at a range of a few meters. [Achu Wilson] found that he could greatly extend the range by as much as 2 kilometers. All he needed to do was build this high-gain antenna.

He already had an idea of what he wanted to use the RF link for, so a directional antenna is no a problem. He chose a biquad setup with a back reflector, then used NEC2 to model the design and tweak it for the best performance possible. It only took him about two hours to complete the build, and manages a 10 dB gain. Not bad for some wire and a scrap of sheet meta.

This is the same transceiver chip used in the SNES wireless mod. If only we had a really powerful set of binoculars we could play the extremely long-distance game of Mario Kart we’ve always dreamed about.